title: Formation of single-walled carbon nanotube thin films enriched with semiconducting nanotubes and their application in photoelectrochemical devices.
abstract: Single-walled carbon nanotube (SWCNT) thin films, containing a high-density of semiconducting nanotubes, were obtained by a gel-centrifugation method. The agarose gel concentration and centrifugation force were optimized to achieve high semiconducting and metallic nanotube separation efficiency at 0.1 wt% agarose gel and 18,000g. The thickness of SWCNT films can be precisely controlled from 65 to 260 nm with adjustable transparency. These SWCNT films were applied in photoelectrochemical devices. Photocurrents generated by semiconducting SWCNT enriched films are 15-35% higher than those by unsorted SWCNT films. This is because of reducing exciton recombination channels as a result of the removal of metallic nanotubes. Thinner films generate higher photocurrents because charge carriers have less chances going in metallic nanotubes for recombination, before they can reach electrodes. Developing more scalable and selective methods for high purity semiconducting SWCNTs is important to further improve the photocurrent generation efficiency by using SWCNT-based photoelectrochemical devices.
authors.affiliation: School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459.
authors.forename: Li
authors.initials: L
authors.lastname: Wei
authors.forename: Noriyasu
authors.initials: N
authors.lastname: Tezuka
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Umeyama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Imahori
authors.forename: Yuan
authors.initials: Y
authors.lastname: Chen
mesh_terms: D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008567:Membranes, Artificial; D036103:Nanotechnology / Q000295:instrumentation*; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure*; D010783:Photometry / Q000295:instrumentation*; D012666:Semiconductors
chemical_list: D008567:Membranes, Artificial; D037742:Nanotubes, Carbon